Pattern mechanism for knitting machines

ABSTRACT

A pattern multiplier to reduce the number of plain links of the chain on a circular knitting machine wherein main and auxiliary ratchets intermittently advance the chain sprocket with the main ratchet advancing the chain greater distances when chain controls of the knitting are required and with the auxiliary ratchet advancing the chain lesser distances when no controls of the knitting are required. The angular pitch of the teeth of the main ratchet is twice that of the teeth of the auxiliary ratchet so the former advances the chain twice the distance of the advance by the latter. Cams on the chain, via a flexible cable, act to raise the main pawl out of action thereby permitting the auxiliary pawl and auxiliary ratchet to continue the advance of the chain.

United States Patent [1 1 Bun [451 Nov. 27, 1973 PATTERN MECHANISM FOR KNITTING MACHINES [75] Inventor: Franco Bini, Firenze, Italy [73] Assignee: Bille S.P.A., Firenze, Italy [22] Filed: Jan. 28, 1972 [21] Appl. No.: 221,567

[30] Foreign Application Priority Data 2,243,277 5/1941 Page 66/154 Primary ExaminerRonald Feldbaum Attorney-Louis Necho [57] ABSTRACT A pattern multiplier to reduce the number of plain links of the chain on a circular knitting machine wherein main and auxiliary ratchets intermittently advance the chain sprocket with the main ratchet advancing the chain greater distances when chain controls of the knitting are required and with the auxiliary ratchet advancing the chain lesser distances when no controls of the knitting are required. The angular pitch of the teeth of the main ratchet is twice that of the teeth of the auxiliary ratchet so the former advances the chain twice the distance of the advance by the latter. Cams on the chain, via a flexible cable, act to raise the main pawl out of action thereby permitting the auxiliary pawl and auxiliary ratchet to continue the advance of the chain.

5 Claims, 4 Drawing Figures PATTERN MECHANISM FOR KNITTING MACHINES The present invention relates generally to the art of knitting and more particularly to the chain control pattern mechanism of circular knitting machinesto reduce the length of the pattern chain.

The pattern control chain of circular knitting machines is made up of individual chain links certain of which have pattern indicia thereon in the form of cams or pins extending therefrom while otherof thechain links are plain with no pattern indicia thereon.

Since the plain links do not control functions of the knitting machines during plain rotary knitting, it is desirable that the number of such plain links be reduced to thereby reduce the overall length of the chain, However, this has heretofore not been possiblesince the chain sprocket is indexed a fixed distance for each plurality of revolutions of the machine. Consequently-the number of the chain links, whether plain or indicia bearing, has been dependent upon the overall number of machine revolutions required for each unit of knitting made on the machine.

'tailed description of a preferred embodiment of the invention as shown in the accompanying drawings, the invention resides in the elements of construction and arrangement of parts of the main and auxiliary ratchets to index the chain sprocket as illustrated and as pointed out in the claims,

IN THE DRAWINGS FIG. 1 is a side view, partly in section, of a portion of the frame of a circular knitting machine showing the pattern drum shaft, a main and an auxiliary ratchet on the shaft and main and auxiliary pawls to selectively advance the ratchets under pattern chain control, in accordance with the present invention.

FIG. 2 is a front view on an enlarged scale of a portion of FIG. 1 showing the control from the pattern chain to inactivate the main ratchet and pawl during plain knitting on the machine.

FIG. 3 is a front view of a portion of the link chain itself, and FIG. 4 is a side view of the chain of FIG. 3 as disposed on the chain sprocket.

In the drawings, the main frame of the machine is indicated at 1 within which a conventional rotary shaft 3 is provided to conventionally turn the needle cylinder (not shown). Disposed on a shaft 5 is a conventional chain sprocket and a chain 7 trained thereof as shown in outline form. The chain 7 is provided with conventional radially extending cam shoulders 7A and 7B and laterally extending cam shoulders 7C, the elements 7A, 7B and 7C conventionally acting through suitable arms or feelers (not shown) to control the type of knitting on the machine. Also provided on chain 7 are laterally extending cam shoulders 7E which are disposed on those portions of the chain which also contains the cams 7A, 7B and 7C, the purpose of cams 7E will be understood as the invention is explained.

Suitably pivoted at 9B on the machine frame 1 is a lever 9 having a roller 9A at one end thereof for contact withthe cams 7E as the chain 7 is advanced. A flexible cable 11, connected to the other-end of lever 9, slides through its cover 11A and is connected to a projecting head 11C which has a compression spring 118 acting thereon. The cable 11 extends through spring 118 and the other end of the cable is anchored at 11D on frame l. When there is no cam 7E acting on roller 9A, the head 11C will project upwardly as moved lower level.

Supported on shaft 5 and operatively related to the chain sprocket to advance the same is a main ratchet 13' and an auxiliary ratchet 15, the angular pitch of the teeth of the former being twice that of the latter. Suitably pivoted on a pin 17 set in frame 1 is one end of a rocking lever 19 having a roller 19A at its other end. Lever 19 is urged against a rotary cam 23 by a suitably anchored tension spring 21, the cam 23 turning in timed relation to the knitting machine rotation. Pivotally mounted at 25 on lever 19 is a main pawl 27 the end 27A of which is adapted to engage the teeth of main ratchet l3 to advance the chain sprocket when permitted to do so by the pattern chain control. Also pivotally mounted at 29 on lever 19 is a second auxiliary pawl 31 the end 31A of which .is adapted to engage the teeth of auxiliary ratchet 15 to advance the chain sprocket when the main pawl 27 is inactive. When the main ratchet is active to advance the chain sprocket, the movement of the former will advance the latter twice the angular distance than when the auxiliary ratchet advances the chain sprocket (with the main pawl inactive).

As lever 19 oscillates, the pawls 27 and 31 are accordingly moved back and forth to have their ends 27A and 31A engage the teeth of ratchets l3 and 15 to advance them step by step. The pawl 31 is pivoted on lever 19 at a point which is half the distance between the pivot points of lever 19 and of pawl 27 so that the pawl 31 has half the stroke of pawl 27. Accordingly, auxiliary pawl end 31A advances auxiliary ratchet 15 an angular pitch distance equal to half that of main pawl end 27A acting on main ratchet 13. When both pawls 27 and 31 are active, the advance of the chain sprocket is controlled by the acfion of pawl 27 on ratchet 13, whereas when pawl 27 is inactive, the advance of the chain sprocket is controlled by the action of pawl 31 on ratchet 15. It will be seen that the auxiliary pawl 31 and auxiliary ratchet 15 will advance the chain sprocket at half the rate of main pawl 27 and main ratchet 13.

It is desired to keep' main pawl 27 inactive so as not to advance the chain (and to let the auxiliary pawl 31 do so) when plain knitting takes place on the machine. During plain knitting no chain control is needed for the same so for this portion of the knitting the chain is formed of plain chain links. By advancing the chain sprocket by auxiliary pawl 31 during plain knitting the chain sprocket will be advanced half the distance it normally would have been moved by the main pawl 27,

3 therefore the chain length'of plain links will be reduced by one-half. 1 l

During plain knitting the plain chain links will have no cams thereon to act on roller 9A so that the head 11C,located under main pawl 27 and urged upwardly by spring 1 1B, is highenough to keep pawl 27 from advancing ratchet 13, thereby to permit the continuously active auxiliary pawl 31 to advance the chain sprocket by its action on ratchet 15. When knitting controls are needed for the fabric and the cams 7A, 7B and 7C are in position to act on the arms or feelers associated therewith, at the same time the cams 7B are in position to act on roller 9A to turn lever 9 to lower the level of head 11C so that main pawl 27 will be active to advance ratchet 13 thereby to advance the chain sprocket (and the chain 7) its usual distance with each movement of ratchet 13. It will be understood that the plain links of the chain may be advanced a still lesser distance with each movement of the chain sprocket, for example, one third of its usual distance, thereby to further reduce the length of the plain link portion of the chain.

I claim:

1. A circular knitting machine having an indexable chain sprocket, a chain having at least one cam on said sprocket and movable therewith, a main ratchet operatively related to and movable with said sprocket, a main pawl to intermittently advance said ratchet a given distance thereby to intermittently advance said sprocket and said chain, an auxiliary ratchet operatively related to and movable with said main ratchet and said sprocket, an auxiliary pawl to intermittently advance said ratchets, said sprocket and said chain a distance less than said given distance, and means operable by said cam to prevent said main pawl from advancing said ratchet at predetermined times.

2. A circular knitting machine as in claim 1 wherein the angular pitch of the teeth of said main ratchet is a multiple of the angular pitch of the teeth of said auxiliary ratchet.

3. A circularknitting machine as in claim 1 wherein said means operable by said cam to prevent said main pawl from advancing said ratchet at predetermined times is operatively connected to said cam through a flexible cable.

4. A circular knitting machine as in claim 1 having a rocking lever and wherein said main and said auxiliary pawls are pivotally mounted upon said rocking lever for reciprocating movement therewith, the pivot point of said auxiliary pawl being located between the pivot points of said lever and of said main pawl.

5. A circular knitting machine as in claim 2, wherein said cable is adapted to raise said main pawl above its pivot point thereby to prevent said main pawl from advahcing said main ratchet. 

1. A circular knitting machine having an indexable chain sprocket, a chain having at least one cam on said sprocket and movable therewith, a main ratchet operatively related to and movable with said sprocket, a main pawl to intermittently advance said ratchet a given distance thereby to intermittently advance said sprocket and said chain, an auxiliary ratchet operatively related to and movable with said main ratchet and said sprocket, an auxiliary pawl to intermittently advance said ratchets, said sprocket and said chain a distance less than said given distance, and means operable by said cam to prevent said main pawl from advancing said ratchet at predetermined times.
 2. A circular knitting machine as in claim 1 wherein the angular pitch of the teeth of said main ratchet is a multiple of the angular pitch of the teeth of said auxiliary ratchet.
 3. A circular knitting machine as in claim 1 wherein said means operable by said cam to prevent said main pawl from advancing said ratchet at predetermined times is operatively connected to said cam through a flexible cable.
 4. A circular knitting machine as in claim 1 having a rocking lever and wherein said main and said auxiliary pawls are pivotally mounted upon said rocking lever for reciprocating movement therewith, the pivot point of said auxiliary pawl being located between the pivot points of said lever and of said main pawl.
 5. A circular knitting machine as in claim 2, wherein said cable is adapted to raise said main pawl above its pivot point thereby to prevent said main pawl from advancing said main ratchet. 